// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

package task

import (
	"context"
	"fmt"
	"os"
	"strings"

	"github.com/joomcode/errorx"
	"github.com/kumose/kmopt/pkg/cluster/ctxt"
	"github.com/kumose/kmopt/pkg/cluster/executor"
)

// RotateSSH is used to rotate ssh key, e.g:
// 1. enable new public key
// 2. revoke old public key
type RotateSSH struct {
	host             string
	deployUser       string
	newPublicKeyPath string
}

// Execute implements the Task interface
func (e *RotateSSH) Execute(ctx context.Context) error {
	return e.exec(ctx)
}

func (e *RotateSSH) exec(ctx context.Context) error {
	wrapError := func(err error) *errorx.Error {
		return ErrEnvInitFailed.Wrap(err, "Failed to Rotate ssh public key on remote host '%s'", e.host)
	}

	exec, found := ctxt.GetInner(ctx).GetExecutor(e.host)
	if !found {
		panic(ErrNoExecutor)
	}

	pubKey, err := os.ReadFile(ctxt.GetInner(ctx).PublicKeyPath)
	if err != nil {
		return wrapError(err)
	}

	newPubKey, err := os.ReadFile(e.newPublicKeyPath)
	if err != nil {
		return wrapError(err)
	}

	sshAuthorizedKeys := executor.FindSSHAuthorizedKeysFile(ctx, exec)

	// enable new key
	cmd := fmt.Sprintf(`echo %s >> %s`, strings.TrimSpace(string(newPubKey)), sshAuthorizedKeys)
	_, _, err = exec.Execute(ctx, cmd, false)
	if err != nil {
		return wrapError(errEnvInitSubCommandFailed.
			Wrap(err, "Failed to write new public key to '%s' for user '%s'", sshAuthorizedKeys, e.deployUser))
	}

	// Revoke old key
	cmd = fmt.Sprintf(`sed -i '\|%[1]s|d' %[2]s`,
		strings.TrimSpace(string(pubKey)), sshAuthorizedKeys)

	_, _, err = exec.Execute(ctx, cmd, false)
	if err != nil {
		return wrapError(errEnvInitSubCommandFailed.
			Wrap(err, "Failed to revoke old key for user '%s'", e.deployUser))
	}

	return nil
}

// Rollback implements the Task interface
func (e *RotateSSH) Rollback(ctx context.Context) error {
	return ErrUnsupportedRollback
}

// String implements the fmt.Stringer interface
func (e *RotateSSH) String() string {
	return fmt.Sprintf("RotateSSH: user=%s, host=%s", e.deployUser, e.host)
}
